1. Field of the Invention
The present invention relates to a sensor system which is suitable for detecting a contact with an object. The sensor system may be a tactile sensor system provided on a surface (e.g., a hand or an entire body surface) of a robot, for example.
2. Description of Related Art
The development of humanoid robots has been in progress. Such humanoid robots are expected to perform sophisticated actions such as touching with a human, autonomously avoiding an obstacle, and grasping and transporting an object. Since sensing of touch is necessary for such actions, a technique for providing a tactile sensor(s) on a hand portion of a robot or the entire body surface of a robot has been studied in recent years (e.g., Japanese Unexamined Patent Application Publication Nos. 2008-281403 and 2006-208248).
A human can distinguish between two different objects by their textures even when they are similar in size and weight, such as between an apple and a pear. Such a high-level sensing function would be more preferable in humanoid robots in the future, and therefore various types of tactile sensors would be in need. For example, it is preferable to simultaneously detect various types of factors such as a vertical stress, a shearing force, slide, a chatter vibration, and a friction.
The high-level sensing for detecting small differences may be achieved by providing various types of sensors. However, a lot of various types of sensors may be required. Therefore, it poses a problem that the manufacturing costs increase enormously. Further, there is another problem that managing various types of small sensors is very troublesome.